It is known from the art that an asynchronous machine can be controlled or managed by means of a control system or management system operating in a field-oriented manner. The control system usually operates on the basis of a detection of a stator current of a stator of the asynchronous machine, a stator voltage of the stator and a rotor position and/or a rotor rotational speed of a rotor of the asynchronous machine.
It is likewise known that the asynchronous machine can be controlled without a rotary encoder by means of a field-oriented control system which is free of a rotary encoder and which can operate in a manner free of direct detection of the rotor position and/or the rotor rotational speed. Management of the asynchronous machine without a rotary encoder can dispense with the provision of an expensive rotary encoder, for example, such that the asynchronous machine can be manufactured cost-effectively and compactly.
DE 196 46 457 A1 and DE 42 09 305 C2 describe methods for the field-oriented control of an asynchronous machine without a rotary encoder.
DE 42 09 305 A1 describes a method and a device for the field-oriented control of asynchronous machines with dynamically high-quality detection of the stator voltages thereof required in the electrically settled state.
DE 195 31 771 A1 describes a method and an apparatus for determining a rotational speed of an encoderless rotating-field machine operated in a field-oriented manner.
DE 102 19 826 A1 describes a method and an apparatus for the field-oriented control of a permanent magnet synchronous machine.